Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
tinh ven » trinh ven, tinh yen, sinh vien
ven cua » ben cua, gen cua, men cua
va tinh » may tinh
cac duc » cac du, cao duc, cac dac
hieu ve » hieu va, hieu van
cua tre » cua te, cuu tre, cua triet
tay hoi » tay ho, tao hoi, tay thai
xay hoi » xa hoi, cay phoi, gay thoi
ky dang » ky nang, ky danh
ve cac » va cac, vien cac

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: ((te sach) or (toc sach)) ky dang ((xay hoi) or (tay hoi)). hieu ve cac duc va tinh ven cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (toc sach)) ky dang ((xay hoi) OR (tay hoi)). hieu ve cac duc va tinh ven cua tre.
• Adding a wildcard symbol may retrieve word variants: ((te sach) or (toc sach)) ky dang ((xay hoi) or (tay hoi)). hieu ve cac duc va tinh ven cua tre*.